John Deere 002035.09 – ICU / HCC: CAN Bus Communication Failure

Indicates a communication failure within the vehicle's Controller Area Network (CAN) bus system, specifically an 'Abnormal Update Rate' (FMI .09). A required data message is not being received from a specific control unit. When logged by the Instrument Control Unit (ICU), it indicates missing messages from the Hitch Control Unit (HCU). When logged by Hitch Valve 1 (HV1) or the Hitch Control Computer (HCC), it signifies a missing message from the HCC itself or a related hitch component.

• 7720
• 7820
• 7920
• 7210J
• 8130
• 8230
• 8330
• 8430
• 8530
• 9100
• 9200
• 9300
• 9400
• 9120
• 9220
• 9320
• 9420
• 9520
• 9230
• 9330
• 9430
• 9530
• 9630
• 9360R
• 9460R
• 9470RT
• 9520RT
• 9570RT

1. 1

   Restart the tractor to see if the communication error clears on its own

2. 2

   Check ICU-related fuses (F15, F22, F24, F30, F35) and HCU-related fuses (F30)

3. 3

   Inspect CAN bus connectors between the ICU and HCU for corrosion, moisture intrusion, loose pins, or damage

4. 4

   Inspect the CAN bus wiring harness (Red, Black, Yellow, Green wires) for chafing, pinching, or breaks

5. 5

   Check CAN circuit terminating resistors (a healthy circuit should read approximately 60 ohms)

6. 6

   Check for proper voltage on the power and ground pins at the HCU connector

1. 1

   Restart the tractor

   Turn the vehicle off, wait a few moments, and restart it to reset communication messages. If the code clears and does not return, no further action is needed.

2. 2

   Replace blown fuses

   If any ICU (F15, F22, F24, F30, F35) or HCU (F30) fuses are blown, replace them. If a fuse blows repeatedly, trace the circuit to locate and repair the underlying short circuit.

3. 3

   Service CAN bus connectors

   Disconnect affected CAN bus connectors, clean them thoroughly with contact cleaner, apply dielectric grease, and firmly reseat them.

4. 4

   Repair or replace wiring

   Repair any physical damage found in the CAN bus wiring harness. If damage is extensive, replace the affected harness section.

5. 5

   Isolate faulty control units

   Disconnect controllers one by one to see if communication is restored. This helps identify if a faulty module is flooding the network with bad data.

6. 6

   Perform dealer-level diagnostics

   If physical inspections and basic isolation fail, use John Deere Service ADVISOR™ to monitor CAN bus traffic, perform specific controller tests, and pinpoint the exact source of the message loss.